Evaluation of different methods (ELISA, IF, EM, PAGE) for the diagnosis of rotavirus infection in piglets.

The study on the prevalence of rotaviral infections among diarrhoetic piglets in 11 commercial farms in Poland was carried out on 531 faecal samples tested using an ELISA to screen for rotavirus. Of these, 169 were found to contain rotavirus antigen (32% of all cases of diarrhoea tested). Those pig herds managed using the Bisprol system had a lower prevalence of rotavirus in pigs with diarrhoea than those faecal samples obtained from Gi-Gi or Agrokomplex Agard farms. To further establish the presence of rotavirus antigen, 28 of those positive in ELISA samples were taken for isolation of the virus using tissue culture; 18 (64%) isolates were successfully adapted into MA-104 cells and the presence of rotavirus confirmed by immunofluorescence (IF) and electron microscopy (EM). In addition, an analysis of the band patterns visualised on PAGE showed 9 distinct electropherotypes for rotaviral dsRNA among the tested specimens. These findings suggest that rotavirus may represent an important contribution to the incidence of diarrhoea in Polish pig herds. The use of ELISA technology provided an efficient and effective means of evaluating the presence of rotavirus antigen in faecal samples and indicates that this procedure is a very useful tool in epidemiological studies, but that other techniques are required to confirm the presence of virus.